Atomically Dispersed Lewis Acid Sites on Pd Metallene Cathode Boosting Durability and Energy Efficiency of Neutral Zn‐air Batteries

Abstract Neutral Zn‐air batteries (ZABs) are promising energy storage systems due to their high theoretical energy density, intrinsic safety, and environmental friendliness. However, the widespread application of neutral ZABs is hindered by poor cycle stability and energy efficiency, primarily due to the limited OH − concentration and ionic conductivity which result in sluggish oxygen reduction/evolution reaction (ORR/OER) kinetics of cathodes. Herein, a strategy is developed to construct atomically dispersed Lewis acid sites (CrO x clusters) on Pd metallene (CrO x /Pd), in which the CrO x clusters can capture the OH − anions to create the localized alkaline environment on Pd catalytic sites. Moreover, the formation of Cr─O─Pd ligands and their electronic modulation can optimize the adsorption/desorption energy of oxygen intermediates to accelerate bifunctional catalytic kinetics. The obtained CrO x /Pd composite exhibits a remarkably small potential gap of ∆ E = 0.767 V (between OER overpotential at 10 mA cm −2 and ORR half‐wave potential) in the neutral electrolyte, enabling high energy efficiency in neutral ZAB. More impressively, the ZAB displays a prolonged cycle life of over 20 000 cycles, which sets a new record in neutral ZAB systems. This work provides a new approach for designing durable and bifunctional efficient electrocatalysts for enhancing the performance of metal‐air batteries in neutral electrolytes.